The goals set for the current year are to elucidate factors involved in low frequency synaptic transmission in the hamster submandibular (parasympathetic) ganglion. We will analyze: 1) the underlying electrical activities of neurons employing a single electrode voltage cllmp technique; 2) the nature of the multi-phased PSP's, which last more than several minutes in response to preganglionic reptititive stimulations, and their pharmacological characteristics, and 3) the function of the postganglionic neuron collateral synapse. These electrophysiological studies will be combined with electronmicroscopic studies: 4) to correlate the calcium-and caffeine-activated cellular activities and 5) to located the postganglionic neuron collateral synapses.